Abstract
Studying the spatiotemporal changes of the northern limit of winter wheat (NLWW) in China is important to ensure regional food security and deal with the effects of climate change. Previous studies mainly used climate indicators to analyze the variation of the potential NLWW in different historical periods, while little attention has been paid to the actual migrations and changes of the NLWW. The objectives of the present study were three-fold: (i) to map the spatial distribution of winter wheat in northern China in 2001, 2007, 2014 and 2019; (ii) to extract the actual NLWW; and (iii) to quantitatively explore the dynamics of the NLWW. First, we adopted the “combining variations before and after estimated heading dates” method to map the winter wheat in northern China based on time series MODIS EVI2 data. Second, we used the kernel density estimation algorithm to extract the actual NLWW in four historical periods. Finally, the fishnet method was utilized to quantitatively analyze the direction and distance of the spatiotemporal changes of the NLWW. The results demonstrated that the NLWW has exhibited a marked fluctuating trend of migration southward, with a 37-km shift in latitude over the past 20 years. The elevation limit of winter wheat planting was around 1600 m; however, the centroid of winter wheat planting has shifted slowly to lower elevations. There was a gap between the actual NLWW and the potential NLWW. The reason for this gap was that the actual NLWW moved southward under the interacting effects of human activities and climate change, while the potential NLWW moved northward due to climate change. The results of this study are of great scientific value in the formulation of winter wheat planting strategies in climate-sensitive areas to respond to climate change and ensure food security.
Highlights
Winter wheat is one of the most important food crops for ensuring food security, and is planted extensively worldwide, providing approximately 20% of human calorie demand [1,2]
FWorinthteer MwhOeaDtIS-derived maps o54f9winter wheat in 2001,324007, 2014 and 2508139, accuracy9a4.s1s7e%ssments wereNocno-nwdinutecrtewdheuatsing Landsat-in2t9erpreted maps of th5e89123033 tile ar6e1a8 in the co9r5r.e3s1p%onding yearFsi[e4ld2]s.urVviesyusaitlelys, the MODIS-es5t7im8 ated maps appeared62t3o be consisten1t20w1 ith the cOoAr=re94s.p75o%nding
In the context of climate change, it is crucial to understand the spatiotemporal shifts of the northern limit of winter wheat (NLWW) in order to develop adaptation strategies and ensure food security in China
Summary
Winter wheat is one of the most important food crops for ensuring food security, and is planted extensively worldwide, providing approximately 20% of human calorie demand [1,2]. Climate change is significantly altering the spatial distribution of winter wheat [3,4]. Understanding the spatiotemporal dynamics of the NLWW is an important foundation for an effective climate change response and winter wheat production strategy formulation [7,8]. Previous studies have demonstrated that the potential NLWW in China has shown a clear northward shift in the historical period, and this shift will continue in the future [10]. This indicates that the area suitable for winter wheat planting has increased [11]. A gap may exist between the potential NLWW and the actual NLWW in China
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.